[PATCH 2/2] smb: invalidate and close cached directory when creating child entries

[Bharath SM <bharathsm.hsk@gmail.com>]

When a parent lease key is passed to the server during a create operation
while holding a directory lease, the server may not send a lease break to
the client. In such cases, it becomes the client’s responsibility to
ensure cache consistency.

This led to a problem where directory listings (e.g., `ls` or `readdir`)
could return stale results after a new file is created.
eg:
ls /mnt/share/
touch /mnt/share/file1
ls /mnt/share/

In this scenario, the final `ls` may not show  `file1` due to the stale
directory cache.

For now, fix this by marking the cached directory as invalid if using
the parent lease key during create, and explicitly closing the cached
directory after successful file creation.

Fixes: 037e1bae588eacf ("smb: client: use ParentLeaseKey in cifs_do_create")

Signed-off-by: Bharath SM <bharathsm@microsoft.com>
---
 fs/smb/client/dir.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/fs/smb/client/dir.c b/fs/smb/client/dir.c
index 1c6e5389c51f..f2c87515dadb 100644
--- a/fs/smb/client/dir.c
+++ b/fs/smb/client/dir.c
@@ -190,6 +190,7 @@ static int cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned
 	int disposition;
 	struct TCP_Server_Info *server = tcon->ses->server;
 	struct cifs_open_parms oparms;
+	struct cached_fid *parent_cfid = NULL;
 	int rdwr_for_fscache = 0;
 	__le32 lease_flags = 0;
 
@@ -313,10 +314,10 @@ static int cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned
 	if (!tcon->unix_ext && (mode & S_IWUGO) == 0)
 		create_options |= CREATE_OPTION_READONLY;
 
+
 retry_open:
 	if (tcon->cfids && direntry->d_parent && server->dialect >= SMB30_PROT_ID) {
-		struct cached_fid *parent_cfid;
-
+		parent_cfid = NULL;
 		spin_lock(&tcon->cfids->cfid_list_lock);
 		list_for_each_entry(parent_cfid, &tcon->cfids->entries, entry) {
 			if (parent_cfid->dentry == direntry->d_parent) {
@@ -327,6 +328,7 @@ static int cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned
 					memcpy(fid->parent_lease_key,
 					       parent_cfid->fid.lease_key,
 					       SMB2_LEASE_KEY_SIZE);
+					parent_cfid->dirents.is_valid = false;
 				}
 				break;
 			}
@@ -355,6 +357,10 @@ static int cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned
 		}
 		goto out;
 	}
+
+	if (parent_cfid && !parent_cfid->dirents.is_valid)
+		close_cached_dir(parent_cfid);
+
 	if (rdwr_for_fscache == 2)
 		cifs_invalidate_cache(inode, FSCACHE_INVAL_DIO_WRITE);
 
-- 
2.43.0